For convenience purposes, it is well known to provide garage doors which utilize a motor to provide opening and closing movements of the door. Motors may also be coupled with other types of movable barriers such as gates, windows, retractable overhangs and the like. An operator is employed to control the motor and related functions with respect to the door. The operator receives command signals for the purpose of opening and closing the door from a wireless remote, from a wired or wireless wall station or other similar device. It is also known to provide safety devices that are connected to the operator for the purpose of detecting an obstruction so that the operator may then take corrective action with the motor to avoid entrapment of the obstruction.
How safety devices are used with a door operator system have evolved from the days of no uniform standard to the currently applied government regulations as embodied in Underwriters Laboratories Standard 325. UL Standard 325 encompasses safety standards for a variety of movable barriers such as gates, draperies, louvers, windows and doors. The standard specifically covers vehicular gate or door operators intended for use with garages and/or parking areas. Such devices require a primary safety system and a secondary safety system which are independent of each other. Primary entrapment systems sense the operator motor's current draw, or motor speed and take the appropriate corrective action if the monitored value is exceeded. Primary systems must be internal within the operator head. Secondary entrapment systems are typically external from the operator head and may include a non-contact or contact type sensor. But, secondary systems may also be internal to the operator head as long as they are independent of the primary system.
One of the more widely used non-contact safety devices is a photo-electric eye which projects a light beam across the door's travel path. If the light beam is interrupted during closure of the door, the operator stops and reverses the travel of the door. Contact type safety devices such as an edge-sensitive pressure switch, which is attached to the bottom edge of the door and runs the complete width of the door, may also be used. Other contact safety devices directly monitor the operating characteristics of the driving motor to determine whether an obstruction is present. Typically, shaft speed of the motor is monitored by projecting an infrared light through an interrupter wheel. Alternatively, Hall effect switches or tachometers can be used to monitor shaft speed. Or, the motor current can be monitored such that when an excessive amount of current is drawn by the motor—which indicates that the motor is working harder than normal—it is presumed that an obstruction has been encountered. It is also known to monitor door speed with a sliding potentiometer, wherein a rate of door position change is equated to the speed of the door and wherein unexpected slowing of the door triggers corrective action by the operator. The secondary entrapment requirement may also be met by providing an operator that is capable of receiving continuous pressure on an actuating device that is in the line of sight of the door and maintains the opening or closing motion until the respective limit position is reached. Regardless of how the safety devices work, their purpose is to ensure that individuals, especially children, are not entrapped by a closing door. Opening forces of the door are also monitored to preclude damage to the operating system for instances where an object or individual is caught upon a door panel as the door moves upwardly.
Safety devices perform their function within the operator's direction control logic sequence where each operational signal sent to the motor controls initiates a different movement of the barrier. For example, if a barrier door is fully-closed, the next user command causes the door to open. If the barrier is fully open, the next user command causes the barrier to close. If the barrier is stopped, partially open, that is, between the fully-open and the fully-closed, then the barrier operator typically uses either one, but not both, of the following controlling logic sequences:    a) Four-Phase Logic: The barrier's next direction is opposite of its last direction. If the barrier's last direction was opening, then the next direction will be closing. If the barrier's last direction was closing, the barrier's next direction will be opening. That is, each user command to the barrier operator steps the barrier's movement through four-phases: Open-Stop-Close-Stop-Open- . . .    b) Open Only Logic: A stopped, partially open barrier can only be commanded to open. Only when the barrier is fully open, can a user command the barrier to close.
Although the operational logic remains the same, there are also motors that have separate directional windings where the first winding moves the door in the first direction and a second winding moves the door in the opposite direction. One exemplary device is shown in U.S. Pat. No. 5,841,253 to Fitzgibbon, et al. The '253 patent discloses a garage door opening and closing apparatus having improved operational safety features. The apparatus includes a control circuit which responds to a number of input stimuli to generate commands to open and close a garage door as well as to stop garage door movement. Three relays respond to the commands via drive circuitry to actually connect door operating voltages to the windings of a door controlling motor. By redundancies in the operation of the three relays, faults in the operation of those relays result in safe door operating conditions. Additionally, the control circuitry upon issuing a door stop command performs a test to determine whether or not the door is still moving. If the door is still moving, door up commands are generated by the control circuitry to place the door in a safe position.
There is also prior art that shows methods of controlling the garage lights from signals emitted from the garage door operator as shown and described in U.S. Pat. No. 5,969,637 Doppelt, et al. The '637 patent discloses a garage door operator with a light control that includes a garage door movement apparatus for moving the garage door in an open and in a close direction within a doorway, a light having an on and an off state, a controller for generating a door movement signal for operating the door movement apparatus and for generating a light enable signal for operating the light in one of a plurality of on and off states, and an obstacle detector for detecting the presence of an obstruction in the doorway. The controller responds to the door state (traveling open, traveling closed and stopped open) in order to control operation of the door and activation of the lights. When the door state indicates the door is stopped open and the obstacle detector detects an obstruction in the doorway, the controller generates a light enable signal for enabling the light. In one embodiment of the invention, the remote actuator (transmitter) of the garage door opener includes a garage door control and a light control. A receiver of the garage door opener responds to a first signal transmitted from the remote actuator in response to activation of the garage door control by opening and closing the door, wherein both operations including turning the light on for a predetermined period. The receiver of the garage door opener additionally responds to a second signal from the remote actuator in response to activating the light control and will turn the lights on without moving the door. Such operation advantageously allows the user to remotely turn the garage lights on from the garage door remote actuator without moving the door. Whenever the user has the garage door remote actuator, he or she can turn the light on or off without operating the garage door opening/closing mechanism.
As noted previously, modern garage door openers likely include a safety arrangement consisting of a light beam directed across the doorway and the opener permits door movement only when no obstructions in the doorway are sensed by the beam. Should the light beam be broken by an obstruction, such as a person, the door will not be permitted to close until the obstruction is removed and the light beam circuit is completed. The '637 patent also discloses that upon sensing that the light beam has been broken, a check is made to determine if the door is stationary and open. If such is the case and the lights are off, the lights of the garage door are turned on. If the door is stationary and open and the lights are on, a momentary turn-off of the lights is enabled. The first situation above turns the lights on whenever a person walks or drives into an open garage in which the lights are off. This provides a safety advantage. The second situation of momentary blinking of the lights notifies persons in the garage when someone has entered the garage.
U.S. Pat. No. 4,491,774 to Schmitz discloses a door operator control system for use in conjunction with a motor driven door operator and light system. The control system includes a first control relay having at least first and second sets of contacts, a second control relay having at least first and second sets of contacts, and interconnection means for interconnecting the contacts and the motor whereby the motor operates in one direction upon actuation of the first relay, and the motor operates in the other direction upon actuation of the second relay, and only the light operates upon actuation of both relays.
In the prior art, garage door operators can create un-anticipated hazards using “four-phase logic” and can be less of a hazard but a nuisance using “open only logic.” To give an example, if a user partially opens their garage door from the fully closed position to a height to allow venting of the garage or egress of a pet and the pet becomes lodged or wedged in the opening, then the user's first reaction may be to activate the door to open freeing the trapped animal. If the operator utilizes “four-phase logic,” the next movement of the door would be in the closing direction, thus increasing the force on the trapped animal. If the operator used “open only logic,” the door would go up to its fully open position and the animal would be freed. However, stopped, partially opened doors controlled by operators with “open only logic” will always go up when activated and must reach the upper fully-open travel limit before it can go down again. Therefore in the evening when the user wants to close the door, the door must travel to its fully-open upper limit, stop, and receive another signal to send it to the closed position.
Garage door operators should undergo a monthly obstruction reversal test where the door is closed on a 2″ by 4″ block of wood and the door must reverse when it hits the obstruction. If the door doesn't reverse, the user is required to reduce the down force by making an adjustment to the force settings or change the full-close limit position and continue to test and adjust until the door reverses. With an “open only logic,” the door always returns to the full-open position before another adjustment is made. Accordingly, making the adjustment for obstruction detection of operators with this type of control logic time is quite time consuming. This is normally considered to be an unacceptable nuisance. Further, if the number of door opening and closing cycles necessary to establish the force settings is excessive, the motor will heat up and the motor's thermal protector will open. This action shuts the motor down for a period of time preventing further door movements until the motor cools down which also results in an unacceptable nuisance.
Normally, as the door is traveling in a downward direction and the door movement is blocked by an obstruction, the door will stop and reverse to the fully open position. During the reversal period, it is common to restrict further door movement commands for a period of time or distance to ensure the door will properly be removed off the object that caused the reversal. Indeed, typical residential garage door operators, upon detecting an obstruction of a downward moving door, stop the door's travel, pause for a short time (0.1 s to 1.0 s typical), and then the door begins upward travel to the full-open position. During this stop-pause-upward sequence, a user may command the door using a remote control or a wired control. A user door command during the stop-pause-upward sequence could stop the door completely, not allowing the sequence to complete. Such a device is disclosed in U.S. Pat. No. 6,239,569. And published patent application US 2003/0154656 A1 discloses a system which inhibits user commands during the stop-pause-upward sequence.
In summary, the prior art logic systems—four phase or open only—work well, but each has a disadvantage. The open only logic system, which causes the barrier to move in an open direction from all stopped positions except the full-open limit position, is considered to be the safest logic system, but it can be inconvenient to the user. This inconvenience results from waiting for the door or barrier to first move to a full-open limit position before moving in a closing direction. The four-phase logic system is easier to use in that a full-open limit position does not need to be obtained in order to move the barrier in a closing direction. But, the four-phase logic can be problematic in situations where an object may be entrapped. Therefore, there is a need in the art for an operator system that provides the safety and convenience benefits of both logic systems while minimizing their disadvantages.